Drawing instrument



J. NASH.

DRAWING INSTRUMENT.

` APPLICATION mtu oms. 19.11. y 1,315,679. Patented Sept. 9,1919.

VWitnesses v(1,/Vratjlnvencor Attorneys iB COLUMnIA PLANnaRM'H C0.. WASHINGTON, D c.

JOHN NASH, OF BELLINGHAM, WASHINGTON.

DRAWING INSTRUMENT.

Specification of Letters Patent. Igrtelltgd Sept. 97 1919,

Application filed December 3, 1917. Serial No. 205,181.

To all Iwiwi/t t may concern.'

lie it known that I, JonN Nnsrr, a citizen of the United States, residing at Bellingham, in the county of vWhatcom and State of lVashington, have invented a new and useful Drawing Instrument, or' which the fol lowing is a specification.

lt is one object of this invention to provide a simple bute'l'ficient instrument for laying oil' the teeth of gear wheels and for like purposes.

The invention aims to provide a novel form of right angled triangle, assembled in a nove] way with a protractor.

It is within the. province of the disclosure to improve generally and to enhance the utility of devices of that type to which the present .invention appertains. e

lVith the above and other objects in view which will appear `as the description proceeds the invention resides in the combination and arrangement of parts `and in the details o1 construction hereinafter described and claimed it being understood that changes in the precise embodimentl of the invention herein disclosed can be made within the scope of what is claimed without departing from the spirit of the invention.

In the accompanying drawings:- i

Figure 1 shows in top plamadrawing in strument constructed in,accordancewith the present invention, some of the graduations haring been omitted; and

Fig. 2 is a section of the instrumentshown in Fig. 1.

The instrument forming the subject matter ol this application may be made of any desired material, and includes a protractor, denoted generally by the numeral 1, and comprising a base 2 and an arcuate arm 3. A. lug 4 projects from the inner edges of the base 1, intermediate the ends of the base, and extends toward the arm 3 of the protractor. The arm 3 is marked oft' into semicircular spaces 5, and into se1ni-circular spa-ces (5 and 7. The space 7 preferably is graduated, as shown at 8, -to indicate degrecs. The space 6, preferably has no graduations and serves to se arate and distinguish the graduations 8 rom graduations 9 individual to the spaces 5. Sonie of the graduations 8 and 9 have been omitted, for the sake of clear-ness, in ythe drawings. The spaces 5 are provided withditcrent numbers of graduations 9. `The innermost space 5 can be graduated into nine parts, and the outermost space 5 may be graduated into twenty-nine parts, the intermediate spaces 5 being graduated as desired.

Stops 10 are secured as shown at 11 to the protractor 1 at the ends oiE the base 2. The stops 10 may be marked, as shown at 12, with the numerals zero and 180, 'for use in connection with the graduations 8. The numeral 14 denotes a right angled triangle, the legs ol which are oil'setas shown at15 to receive the arcuate arm 3 of the protractor 1. At its right angle, the triangle 14 has an extension 16 which overlaps the base 2 of the protractor 1. A reinforcing plate 17 is superposed on the extension 16 and has a wing 18 overlapping the body portion of the triangle 14,7the wing I18 being secured as indicated at 19 to the body of the triangle, and the plat'e 17 secured as indicated at 20 to the extension 16 of the triangle.

`The numeral 21 denotes `a clamp screw, one` end ot which is fixed in the base 2 of `the protractor 1. The `clamp screw 21 `is threaded onithe screw 21 and is adapted to` be clamped down on the reinforcing plate 17. The numeral 24 denotes a tubular pivot screw including a hub 25 on which the reinforcing plate 17 and the extension 16 of the triangle 14 are mounted to swing, the hub having a reduced end 26 secured in the lug 4 oi the base 2 of the protractor 1. A nut 27 is threaded on the tubular pivot screw 24 and coperaties with the reinforcing plate 17 to hold the triangle 14 on the pivot screw for swinging movement. The nut 27 is retained by a lock nut 2S threaded on the pivot screw 24` A second screw 29 is threaded into the tubular pivot screw 24 and includes a center point 30. Near the iducial edges 34 of the legs of the right angled triangle 14, the offset portions 15 of the triangle are provided with Zero marks 31 coperating with the space 7, with ninety degree marks coperating with the space 6, and with numerals 33, denoting how many of the graduations 9 there are lin each of the spaces 5. The triangle 14 includes a curved inner edge 35 coactingI with the curved periphery of the arm 3 of the protractor 1 and carrying a vernier scale 36 coperating with the graduations 8.

In practical operation, the triangle 14 may be swung on the pivot screw 24 the screw 29 being advanced so that the point 30 thereof may exercise its well known function. lVhen the triangle 14 is swung on the pivot screw 14, the clamp screw 21 moves in ,the registering slots 22 of the parts 17 and 16. By tightening down the nut 23, the triangle 14may` be held in any position to which it may have been swung.

The fiducial edges 34 of the legs of the triangle may be used in connection with the graduations 8 or with the graduations 9. 'When the graduations 8 are used, the vernier 36, coperating the graduations 8 gives a closer reading of the angle than that defined by the graduations 8. Vhen the edges 34 of the triangle come into abutment with the stops 10, alternately, one of the said edges .34 may be used, in connection with the iducial edge 37 of the base 2 of the protractor, to lay off a right angle. The edges 34 may be used in connection with the various graduations 9, to lay off gear teeth, and the numeral 33 direct the attention of the operator to the proper space to be used when it is desired that the gear wheel shall have a specilied number of teeth. The fiducial edge 39 of the hypotenuse of the right angled triangle 14 may be used for drawing inclined lines with respect to the lines deter-mined by the ducial edges 34, and for many other purposes. ings 38 in the triangle 14, to facilitate the hanging up of the instrument, to aid the operator in drawing small circles, and for Copies this patent may be obtained for ve cents each, by addressing the lCommissioner .of Patents,

There may be openother purposes which will suggest them-- selves readily to the user.

Having thus described the invention what is claimed is 1. In a drawingl instrument, a protractor comprising a base, and an arcuate arm havbe disposed in a common plane with the arm; a pivot element connecting the eXtension with the hase; a stud on the'base and extended through the slot; and a clamping device on the stud and cooperating with the extension.

2. In a drawinginstrument, a protractor comprising a base, and an arcuate arm having graduations; a right-angled triangle the legs of which deine iducial edges cooperating with the graduations, the triangle being provided at its right angle, with an extension overlapped on the base; a reinforcing plate secured to the extension of the triangle and secured to the body of the triangle, the plate and the extension having an arcuate slot; a pivot element mounted in the base and passing through the plate and the extension; a stud carried by the base and passing through the slot; a holding means on the pivot element and cooperating with the plate; and a clamping device on the stud and coperating .with the plate.

In testimony'that I claim the foregoing as my own I have hereto aiiXed my signature in the presence of two witnesses.

JOHN NASH.

Witnesses W. M. Gnow,

MARGARET GronoN.

Washington, D. C." 

